Certified Tumor Registrar (CTR) Practice Exam

A tumor described as anaplastic is classified as which type?

1. Well-differentiated

2. Moderately differentiated

3. Undifferentiated

4. Low-grade

The correct answer is: Undifferentiated

Anaplastic tumors are characterized by a high degree of cellular abnormality and a lack of differentiation. This means the cells do not resemble the normal cells of the tissue from which they originate, making them undifferentiated. The term "anaplastic" specifically refers to the loss of the specialized features of the original cell type, indicating that the tumor is highly aggressive and often associated with a poorer prognosis. Unlike well-differentiated or moderately differentiated tumors, which maintain some characteristics of the original tissue and thus have various levels of organization and function, anaplastic tumors do not exhibit such differentiation. Similarly, low-grade tumors imply a slower-growing and less aggressive nature, opposite to the characteristics of anaplastic tumors. Thus, the classification of an anaplastic tumor as undifferentiated is accurate and highlights the severity and traits associated with this tumor type.